Various devices are known for measuring perimeters but these are mainly cumbersome and inaccurate, at least two disadvantages that cannot be readily tolerated when precision measuring or sizing is required, particularly in the optical field, as in the sizing of lenses for spectacles, for example.
According to the present invention, a simple, light-weight sizer is provided, capable of being easily held and handled during placement of the lens to be measured and further operable by one hand to tighten the sizing tape peripherally about the lens. The tool comprises a base on which is mounted a handle movable to vary the size of a loop within which the lens or comparable product is placed. The loop is part of a measuring tape or like element, one end of which is affixed to the base and the other end of which is attached to the handle. Another feature of the invention resides in the provision of a lid or cover which, in operative mode, overlies the looped tape and serves to stabilize the tape as well as to confine the lens in better fashion. The lid may be swung away to a displaced mode enabling removal and replacement of lenses. The tool is accurate in use, fool-proof and unlikely to get out of order.
Further objects and features of the invention will become apparent as the present disclosure progresses.